Existing ignition systems of common cooker hobs include an igniter, a thermocouple, and solenoid valve connected with thermocouple. The igniter can ignite the cooker hob with a pulsed high voltage spark produced by igniter and maintain the flame by the thermocouple and solenoid valve. When the user presses and turns on the existing igniter knob on a cooker hob, the knob must be held for a time period until the flame combustion stabilizes before releasing the igniter knob. Premature release of the knob before the thermocouple has reached its operating temperature will cause the solenoid valve to close, shutting off the burner. The thermocouple provides sufficient power to hold the valve open when the thermocouple reaches operating temperature.
EP1739351 is directed to providing a fail-safe thermocouple latched gas supply arrangement which does not require the user to hold the igniter knob in the operated state once it has been operated. The specification discloses a gas ignition system including a capacitor from which an electrical signal is obtained to temporarily supply the safety valve. The capacitor is charged using a switch to temporarily connect the capacitor to the alternating mains voltage and conditioning means are used for converting the electrical signal from the capacitor for application to the safety valve. Charging of the capacitor is achieved simultaneously with the operation of the igniter knob. The capacitor is charged from the mains through a rectifier and regulator circuit. The decay of the capacitor charge through the conditioning circuit and solenoid provides a time delay to hold the solenoid operated gas valve open. This makes the system independent of a subsequent mains power failure.